effective
- 01 B1 Intermediate
adj.producing the result that you wanted or intended.
adj.successful in producing a desired or intended result. Often used to describe solutions, treatments, or methods.
Simple“The new medicine was very effective at reducing her headache quickly.”
In context“The marketing campaign proved highly effective, resulting in a twenty percent increase in new subscriptions over the first quarter.”
UsageCommonly modifies nouns like 'method', 'solution', 'treatment', or 'way'.
PitfallHe is a very effective worker because he never wastes time. He is a very efficient worker because he never wastes time.Use 'effective' for things that get the right result; use 'efficient' for things that work quickly without wasting time or effort.
SynonymsAntonyms - 02 B2 Upper Intermediate
adj.starting to be used or starting to be a law.
adj.coming into operation or effect; officially in use or valid from a specific time.
Simple“The new tax rules will be effective from the first of January.”
In context“The revised safety regulations become effective immediately, and all site managers must ensure compliance by the end of the business day.”
UsageOften followed by the preposition 'from' when indicating a start date.
- 03 C1 Advanced
adj.the real or actual situation, even if it is not the official one.
adj.existing in fact, though not necessarily intended or officially acknowledged.
Simple“Although he is the assistant, he is the effective leader of the team.”
In context“The effective cost of the loan was much higher than the advertised interest rate once the hidden fees were included.”
Teacher's tipIn academic contexts, this sense contrasts 'effective' (the reality) with 'nominal' (the name or theory).
Antonyms - 04 C2 Proficiency
n.a soldier who is healthy and ready to fight.
n.a soldier or member of a military unit who is fit for active service.
Simple“The general counted his effectives before the morning march.”
In context“After the long winter campaign, the regiment's total number of effectives had dropped to less than half of its original strength.”
Synonyms
effective vs efficient — Effective means a thing works to get the job done, while efficient means it works without wasting time, money, or energy.
Usage effective ways · effective at reducing · appreciation effective
From French effectif, from Latin effectīvus (“productive; effective”), from efficiō (“I make; I bring about”), equivalent to effect + -ive.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.